<p>
  <button id="enable" (click)="scrollStrategy.enable()">Enable scroll blocking</button>
  <button id="disable" (click)="scrollStrategy.disable()">Disable scroll blocking</button>
</p>
<div class="demo-spacer demo-spacer-vertical"></div>
<!-- this one needs a tabindex so protractor can trigger key presses inside it -->
<div class="demo-scroller" id="scroller" tabindex="-1">
  <div class="demo-scroller-spacer"></div>
</div>
<div class="demo-spacer demo-spacer-horizontal"></div>
